This paper reviews some of the major aquatic weeds in New Zealand lakes and discusses some of the problems they cause. Approaches to the management of nuisance weed beds are also discussed. New Zealand's indigenous aquatic flora has proved susceptible to invasion with many of our marginal and submerged species being replaced by dense, tall-growing weed species. A variety of management approaches are discussed including ‘leave alone’ strategies and targeted control of nuisance weed beds. Mechanical control of nuisance weeds has tended to focus on problems associated with strandings (e.g., removal of shoreline strandings and at hydroelectric station intakes), but refinement of removal methods at their source is continuing. Chemical control of aquatic weeds is an effective option for target weeds of national importance (e.g., water hyacinth and salvinia) and for specific waterbodies where an acceptable degree of selective control can be achieved. Research results using grass carp have confirmed eradication ofEgeriais possible in small waterbodies and this may be followed by native plant recovery; while similar trials onHydrillahave achieved effective control, but the question of eradication is still unresolved on account of continuing tuber viability within lake sediments.